Counting apparatus



March 1953 H. E. CRADDUCK COUNTING APPARATUS Filed Feb. 24, 1951 lNl/EN TOR H.451 CRADDUCK [BY QM Patented Mar. 10, 1953 COUNTING APPARATUS Henry E. Cradduck, Amesbury, Mass., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application February 24, 1951, Serial No. 212,647

7 Claims. 1

This invention relates to counting apparatus and particularly to the problem of counting a succession of irregularly occurring events which have no direct relation to the rotations or traverse of any member capable of driving a mechanical counting mechanism. A problem of this type arises in connection with winding coils on toroidal cores. These coils an; usually wound at high speeds by machines of a now well-known type as shown, for example, in Patents 2,192,694 and 2,326,969 to Quinlan. Such machines have a positively driven annular shuttle interlinked with a toroidal core on which a coil is to be wound and carry a supply of wire which is fed oil to the core as required by a slider on H the shuttle. As the winding builds up the turns of the successive layers require progressively greater lengths of Wire so that the slip between the slider and shuttle increases, but at all times the slider passes through the toroid once for each turn applied to the core. There is, however, no definite predictable relation between the revolutions of the shuttle and the number of turns wound on the core. Similarly, due to other variables such as the variations in space factor of completed coils, there is no accurate relation between the total length of wire used and the number of turns in a coil. While the passes of the slider correspond to the number of turns, it is impracticable to drive a mechanical counter directly from the slider. Since the inductance of such coils often must be held within close limits, it is highly desirable to have some accurate means for counting the turns as they are wound on the core.

One object of this invention therefore is apparatus suitable for counting accurately the rotations or traverses of a moving member such as the slider of a toroidal coil winding machine.

Another object of the invention is to count the turns of a strand as they are wound on a core.

According to the invention, means is provided for driving a conventional mechanical counter at either of two speeds, one slightly higher and the other slightly lower than the rate of the desired count. The counter is driven at one speed until the accumulated angular error of the counter drive shaft reaches a given value at Which time the counter speed is changed automatically to the other value to maintain the desired accuracy in the count registered.

In one embodiment of the invention, as applied to counting the turns being wound on a toroidal core, clutches disposed between the shuttle and the two counter driving mechanisms have windings energized over circuits closed alternately under the joint control of contacts operated once for each turn applied to the core and contacts operated by the shaft driving the counter. The first contacts may be conveniently operated by the slider each time it passes a given point in its path. When the angular position of the counter shaft leads or lags its proper position with respect to the slider by, for example, about one-half revolution, circuits are established for closing the operating circuit of one clutch and opening the operating circuit of the other to increase or decrease the speed of the counter as required.

In the single figure of the drawing illustrating the invention as used in counting the turns applied to a toroidal core, the shuttle structure I carrying a supply of wire 2 is interlinked with an annular core 3 clamped in position for limited rotation about its vertical axis to distribute the winding by conventional means, not shown. The shuttle structure is driven by a pinion 4 on the drive shaft 5 and is held in position by idler pinions 6 and 1. The shaft 5 also carries a gear 8 driving a gear 9 on a shaft ID to which is fixed a conventional dual electro-magnetic clutch unit II. This unit has external slip rings l2, l3 and M for brushes l5, I6 and I! through which current is supplied to the windings l8 and IQ of the clutches. When either winding is energized it magnetizes the clutch face opposite the clutch plate 20 or 2| causing it and the associated gear 22 or 23 to revolve with the unit I I.

A conventional mechanical counter 24 has a drive shaft 25 to which are keyed gears 26 and 21 meshing with the gears 22 and 23 respectively. The gear ratios are such that when the gear 23 is driving the shaft 25, the counter is running slightly faster than the maximum speed of the slider 28 and when the gear 22 is engaged the counter is running slightly slower than the minimum speed of the slider. Since the slider slips back on the shuttle a linear distance equal to the length of wire applied to the core and the length of Wire per coil turn increases as the winding builds up, it will be evident that the average slider speed varies between two values both less than the shuttle speed. In each case the values of these maximum and minimum slider speeds will depend on various factors such as the ratio of the shuttle circumference to the cross section of the core and the depth of winding to be applied to the core. The maximum slider speed is, of course, only slightly less than the known shuttle speed and the, minimum slider speed can be readily determined approximately'for the particular coils to be wound. In one instance the gear ratios were chosen so that the slower counter speed was about 10% less than the faster speed. The circuit shown for selectively energizing the windings I8 and IQ of the clutch unit comprises two gas-filled trigger tubes 29 and 30, a conventional rectifier and filter unit 3| connected to a source 32 of alternating current for supplying direct current to the windings, and control circuits for the tubes including a contact 33 mounted in the path of the slider 28 and a rotary switch 34 on the shaft 25.

The frame of the winding machine is grounded and the shuttle is therefore always at ground potential as indicated by the ground connection 35. Contact 33 is supported in fixed position on the frame by means, not shown, but which insulate the contact from the machine so that it is grounded momentarily only once per revolution as the slider passes. The switch 34 is essentially a device for connecting the control electrodes 36 and 31 of the tubes to the contact 33 once per revolution of the countershaft 25 and it may comprise a disc of insulating material rotating with the shaft and having a short conducting segment 38 for momentarily connecting brush 39 to brush 4|! and brush 4| to brush 42.

The anodes 43 and 44 of the tubes are connected together by a condenser 45 which, in a manner to be explained, resets either tube when the other is fired so that only one clutch winding is energized at a time. Plate potential for the tubes is supplied from the unit 3| over conductor 46 and slip ring l6 through the clutch windings l8 and I9, slip rings l and i1, conductors 4'! and 48, and resistors 49 and 50 to the plates 43 and 44 respectively. The cathodes 5| and 52 are both biased positively by the potential drop in resistor 53 due to current through either tube. Resistors 54 and 55 and ground connection 56 form a voltage dividing network across the output leads 46 and 57 of the unit 3| such that the potential drop across resistor 55 provides tube firing potential for either tube when its grid is grounded by the contact 33.

When switch 59 is first closed to supply power to the unit 3|, resistor 53 is providing no bias since neither tube is conducting. The plates are at high .positive potential, however, and depending on the constants of the tubes one or the other will fire first and in so doing will positively bias the cathode of the other and prevent it from firing. Assume then that tube 29 fires completing the circuit of winding IQ of the clutch and locking gear 23 to the shaft It. Then when power is applied to the machine and the shaft 5 begins to drive the shuttle to apply a winding to the core 3, the counter 24 also is driven by gear 23 to register the turn count which, for the case assumed, will tend to become slightly higher than its proper value. As soon, however, as the shaft 25 has advanced with respect to the slider to the point where segment 33 of the disc 34 is bridging the brushes 4| and 42 when the slider 28 grounds the contact 33, electrode 31 of the tube 30 is momentarily grounded over conductors 5'1 and 58. Under this condition electrode 31 is positively biased by the drop in resistor 55 which is sumciently in excess of the negative bias due to resistor 53 to cause the tube 30 to fire.

When the tubes are not conducting their plates are at relatively high potential such as +180 volts but when they are conducting the potential drops in resistors 49 and 50 reducing the plate 4 potentials to a relatively low value such as +20 volts. With tube 29 conducting and before tube 30 fires, the left plate of condenser 45 is therefore at +20 volts and the right plate is at +180 volts. When tube 30 fires, as explained above, there will accordingly be a volt negative pulse applied to plate 43 of tube 29 which momentarily drives it negative with respect to its cathode 5|, thereby resetting the tube. Clutch winding I9 is therefore deenergized almost simultaneously "with the energizing of clutch winding It so that gear 23 is released and gear 22 is engaged by the clutch causing the counter to be driven at slightly less than theslider speed.

Some time later, when the slider has overtaken the counter and the lag of shaft 25 approaches contact 33 will be grounded while segment 38 is bridging the brushes 39 and 40. The electrode 36 of tube 29 will then be momentarily grounded and therefore positively biased by the drop in resistor 55. The tube 29 then fires energizing winding I9 and causing gear 23 to drive the countershaft at the higher speed again. At the same time, the sudden drop in potential at the plate 43 results in a ne ative pulse through condenser 45 which momentarily drives plate 44 negative with respect to its cathode resetting tube 30, deenergizing winding l8 and releasing the gear 22.

The frequency at which the speed of the counter is changed will vary with the magnitude of the difference in the relative speeds of the counter and slider. It will be evident, however, from the foregoing description, that whenever the counter lags or leads the slider by about onehalf turn, the proper tube will fire to change the counter speed in the direction necessary to restore the counter shaft to its proper angular position and that the counter reading accordingly will always be correct within this degree of accuracy.

Apparatus of this type has been found capable of making an accurate count at much higher speeds than practicable with impulse type counters and it has the further advantage of being capable of operating reliably for long periods with very little maintenance.

While the invention has been described with reference to a toroidal coil winding machine it is to be understood that this is only one application of the principles of the invention. Various other applications and modifications of the apparatus and circuits shown, embodying the principles of the invention and falling within its spirit and scope, will occur to those skilled in the art.

What is claimed is:

1. Counting apparatus comprising a first contact closed once for each of a succession of events to be counted, a mechanical counting device having a drive shaft and means for registering the rotations of the shaft, two driving means selectively connectable to the shaft to drive the counter at either of two speeds, one higher and the other lower than the frequency of the events to be counted, two other contacts on opposite sides of the shaft, means for closing each other contact once per revolution of the shaft and means energized during the simultaneous closure of, the first contact and either of the other contacts for selectively connectin one of thedriving means to the shaft and disconnecting the other driving means from the shaft.

2. The combination with a rotating member and a second member slidably mounted thereon and rotating therewith with variable slip, of apparatus for accurately counting the revolutions of the second member comprising a counter having a drive shaft, means for driving the shaft at a speed higher than the speed of the second member, means for driving the shaft at a speed lower than the speed of the second member, contacts operated once per revolution of the second member, other contacts operated once per revolution of the counter drive shaft and means under the joint control of the contacts for selectively connecting the driving means to the counter drive shaft.

3. In a toroidal coil winding machine having a shuttle carrying a supply of Wire, means for rotating the shuttle and a slider on the shuttle for payin off Wire to a core as the shuttle rotates, apparatus for counting the turns of wire applied to a core comprising a counter having a rotatable shaft, separate means for driving the shaft at speeds higher than and lower than the slider speed, contacts operated by the slider, other contacts operated by the counter drive shaft and means under the joint control of the contacts for selectively connecting the driving means to the counter drive shaft.

4. The combination with a toroidal coil winding machine including a drive shaft, a shuttle driven by the shaft and interlinlring an annular core and a slider on the shuttle paying of]? wire from the shuttle to the core, of means for counting the turns of wire applied to the core comprising a turns registering counter having an operatin shaft, two driving connections, each including an electromagnetic clutch, between the drive shaft and the counter operating shaft, one of the said connections being operative to drive the counter faster than the slider rotates and the other connection being operative to drive the counter slower than the slider rotates, a slider contact operated once per revolution of the slider, two counter contacts, operated once per revolution of the counter operating shaft, disposed in positions substantially diametrically opposite with respect to the shaft, means responsive during the simultaneous disclosure of the slider contact and one of the counter contacts for energizing one of the clutches, means responsive during the simultaneous disclosure of the slider contact and the other counter contact for energizing the other clutch and means responsive to the energization of either clutch for deenergizing the other.

5. The combination with a rotating member, a second member rotatin therewith with unknown slip and means for driving the rotating member, of means for counting the rotations of the second member comprising a counting device having an operating shaft, two power transmitting connections including clutches for selectively coupling the operating shaft to the driving means to drive the device faster or slower than the speed of the second member, an operating circuit including a trigger tube for each clutch, a source of tube firing potential, a control anode for each tube, a contact momentarily connected to said source once per revolution of the second member, circuit connections from the contact to each control anode, normally open contacts in each connection, means operated by the counter operating shaft for momentarily and periodically closing the normally open contacts and means responsive to the closure of either clutch operating circuit for automatically opening the other. 6. Apparatus for counting the rotations of a member rotating at variable speeds lying within a predetermined range comprising a counter having an operating shaft, two electron tubes, means controlled by one of the tubes for driving the shaft at a speed greater than the maximum speed of the member, means controlled by the other tube for driving the shaft at a speed less than the minimum speed of the member, a source of control potential for the tubes, circuits for connecting said source to the tubes, a normally open contact common to the circuits and closed momentarily once per revolution of the member and other normally open contacts in each circuit closed momentarily once per revolution of the shaft but at different angular positions of the shaft.

7. Apparatus for accurately counting the operations of a member moving at an approximately known rate, comprising a counting device having a drive shaft, two means for driving the shaft at speeds greater than and less than the said known rate, two gas filled tubes each having a cathode, an anode and a control electrode for selectively controlling the connection of the driving means to the shaft, a source of potential for the tubes, firing circuits including a contact momentarily closed by each operation of the member for applying potential from said source between the control electrodes and cathodes of the tubes, normally open contacts in each circuit, means driven by the shaft for alternately closing the above contacts for momentarily preparing the firing circuits for closure by the operations of the member and means automatically effective upon the firing of one tube for resetting the other.

HENRY E. CRADDUCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,702,475 Jahnig Feb. 19, 1929 2,019,286 Arber Oct. 29, 1935 2,339,976 Brown Jan. 25, 1944 2,352,050 Wegener June 20, 1944 2,427,079 Werth Sept. 9, 1947 

